Common Lesions in the Male Reproductive Tract of Cats and Dogs

Histopathological changes in testicular lesions in cats

OBJECTIVES

The aim of this retrospective study was to describe the neoplastic and non-neoplastic lesions seen on histopathological examination of cat testes in Hong Kong between 2018 and 2024.

METHODS

A total of 26 single or dual testes samples were collected from 18 cats by veterinarians at 14 veterinary clinics and submitted for histopathological examination. Laboratory records, including signalment, lesion location, age, breed and histopathological findings, were reviewed for each cat.

RESULTS

Neoplastic testicular lesions were seen in three older cats (median age 8.5 years; range 3-17) compared with 18 non-neoplastic lesions in 15 cats (median age 1 year; range 0.5-3). The most common non-neoplastic lesions included inflammation (in the testes, epididymis, tunics and ductus deferens), cryptorchidism, and one case each of polyorchidism and epididymal cyst formation. Two of the testes with inflammation were identified on immunohistochemical staining as feline coronavirus-infected and one pair of testes was associated with the presence of extracellular Gram-negative bacteria at the lesion site. Three different neoplastic lesions were identified, one each of Sertoli cell tumour, leiomyoma and fibrosarcoma.

CONCLUSIONS AND RELEVANCE

Non-neoplastic testicular lesions were most common, including inflammation, cryptorchidism, polyorchidism and epididymal cysts. To our knowledge, leiomyoma and fibrosarcoma have not been reported in cat testes before and represent important differential diagnoses for testicular lesions.

Ultrasound-Based Technologies for the Evaluation of Testicles in the Dog: Keystones and Breakthroughs

Ultrasonography is a valuable diagnostic tool extensively used in the andrology of human and domestic animals, including dogs. This review aims to provide an overview of various technologies based on ultrasound, from the basic B-Mode ultrasonography to the more recent advancements, such as contrast-enhanced ultrasonography (CEUS) and ultrasound elastography (UEl), all of which are utilized in the evaluation of canine testicles. The review outlines the principles behind each of these technologies and discusses their application in assessing normal and abnormal testicular conditions. B-mode canine testicular ultrasonography primarily focuses on detecting focal lesions but has limitations in terms of objectivity. Other technologies, including Doppler ultrasonography, B-Flow, and CEUS, allow for the characterization of vascular patterns, which could be further measured using specific applications like spectral Doppler or quantitative CEUS. Additionally, ultrasound elastography enables the assessment of parenchyma stiffness both qualitatively and quantitatively. These ultrasound-based technologies play a crucial role in andrology by providing valuable information for evaluating testicular function and integrity, aiding in the identification of pathological conditions that may impact the health and quality of life of male dogs.

Assessment of the utility of platelet indices to diagnose clinical benign prostatic hyperplasia in dogs

Introduction

Platelet indices changes in severely ill people and in dogs with inflammation are compatible findings. This study aimed to compare platelet indices between dogs with clinical benign prostatic hyperplasia (BPH) and healthy controls. Additionally, to determine whether there is a correlation between the relative prostatic size (S _rel) and the platelet indices in BPH dogs.

Methods

Thirty-five adult intact male dogs of different breeds were allocated to the experimental groups: dogs with clinical BPH (groups A; n = 24; median age of 6 years; the median weight of 8.50 kg) and healthy dogs (group B; n = 11; median age 5.50 years; the median weight of 7.00 kg) based on physical examination, clinical signs, and S _rel detected by ultrasonographic findings. The individual prostatic volume (IPV) was divided by the expected prostatic volume (EPV) to determine the relative prostatic size in dogs over 4 years old. Platelet indices were compared between the two groups, and a correlation between S _rel and these indices was calculated.

Results

The median S _rel of dogs in group A was significantly higher (P = 0.001), and the mean plateletcrit (PCT) was significantly lower (P = 0.003) compared with those in group B. S _rel showed a significant negative correlation with PLT and PCT (r = -0.388; P = 0.02 and r = -0.402; P = 0.01). Receiver operating characteristic (ROC) analysis showed PLT and PCT thresholds for estimating S _rel > 1 with 75% and 87.5% sensitivity and 71.82 and 63.64% specificity.

Discussion

The findings of this study support the use of platelet indices like PLT and PCT to detect clinical BPH in dogs. However, more research is needed to confirm their utility in conjunction with other previously described diagnostic factors.

Infertility In Toms: Clinical approach, experiences and challenges

PRACTICAL RELEVANCE

An infertile tom used to be a relatively rare presentation in feline practice. However, as a result of breeding strategies targeting specific morphological/behavioural traits, and the influence of inbreeding (especially practised in rare breeds), among other factors, feline infertility has become a genuine clinical problem. Furthermore, increased interest among cat breeders and pet owners in diagnosing and treating an 'unsuccessful' tom (including using assisted reproductive techniques [ARTs]), has made such patients more commonplace in veterinary practice.

CLINICAL CHALLENGES

A definitive cause for male infertility is often difficult to identify. One of the biggest challenges is the lack of fertility-based reference values for semen quality and hormone levels. Moreover, the literature in this field is scant and many reproductive tract conditions described in other species have not been reported in cats. The establishment of diagnostic tools and algorithms is essential to facilitate a reliable assessment of fertility potential.

GLOBAL IMPORTANCE

There is a growing demand for appropriate veterinary care relating to feline reproduction. There is an expectation among breeders, particularly of pedigree cats of high breeding value, that the same options widely used for dogs (including ARTs) should also be available for cats.

EQUIPMENT AND TECHNICAL SKILLS

Equipment required for investigating male infertility includes a microscope and ultrasound machine; a blood analyser may also be useful, but samples can instead be sent to a laboratory. The skills required are often already performed by veterinarians; for example, catheterising the urethra, performing ultrasonography and blood sampling.

EVIDENCE BASE

There are some reports of fertility problems in male cats in the literature, but this area of feline reproduction is still relatively undeveloped. This review draws on the comprehensive knowledge developed and shared by specialists in this field, and is supported by the authors' own clinical experience.

A Review on Canine and Feline Prostate Pathology

Prostatic diseases are very common in male dogs, accounting for 3–10% of cases submitted to the veterinary practitioners. Commonly reported canine prostatic disorders include prostatic hyperplasia, prostatitis, prostatic cysts and prostatic carcinoma. However, clinical signs may be non-specific, or many cases are asymptomatic, thus leading to a difficult estimation of the actual prevalence of clinical cases. On the other side, because of the rare occurrence of prostate disease in cats, very little is known about pathogenesis, diagnostic approaches and treatment. The goal of this review is to provide detailed clinical and pathological overview of the feline and canine prostatic pathology, including the most up-to-date classification systems and histological findings. Emphasis is places on gross, cytological and histological features that are critical to reach a definitive diagnosis for a proper treatment and prognosis.

Comparative pathology of dog and human prostate cancer

Though relatively rare in dogs, prostate cancer (PCa) is the most common non-cutaneous cancer in men. Human and canine prostate glands share many functional, anatomical and physiological features. Due to these similarities, canine PCa has been proposed as a model for PCa in men. PCa is typically androgen-dependent at diagnosis in men and for this reason, androgen deprivation therapies (ADT) are important treatments for advanced PCa in men. In contrast, there is some evidence that PCa is diagnosed more commonly in castrate dogs, at which point, limited therapeutic options are available. In men, a major limitation of current ADT is that progression to a lethal and incurable form of PCa, termed castrate-resistant prostate cancer (CRPC), is common. There is, therefore, an urgent need for a better understanding of the mechanism of PCa initiation and progression to CRPC to enable the development of novel therapeutic approaches. This review focuses on the functional, physiological, endocrine and histopathological similarities and differences in the prostate gland of these species. In particular, we focus on common physiological roles for androgen signalling in the prostate of men and dogs, we review the short- and longer-term effects of castration on PCa incidence and progression in the dog and relate how this knowledge may be relevant to understanding the mechanisms of CRPC in men.

Computer-assisted sperm analysis and comparative diagnostic imaging of benign prostatic hyperplasia in dogs by ultrasound, X-ray and computed tomography

Early diagnosis of benign prostatic hyperplasia (BPH) in dogs using imaging methods has become increasingly prevalent in recent years. That allows accurate differentiation of BPH from other diseases, as well as timely prophylaxis and treatment. The aim of the research was to make a comparative analysis of BPH diagnosis by ultrasound, X-ray and computed tomography (CT) and computer-assisted sperm analysis (CASA) of ejaculates from sexually mature male dogs. Two hundred and fifty patients of different breeds, 80 of whom with previous clinical history and BPH-related complaints at 3 to 7 years of age, were followed. The results of echographic studies of dogs with clinical signs of BPH showed structural prostate changes. Focal inflammation, small or larger intra- or paraprostatic cysts (7%), neoplasia (3%), acute or chronic prostatitis (15%) and prostate abscesses (3%) were detected. The remaining 72% of patients demonstrated evidence of hypo -to hyper heterogenic parenchyma with moderate heterogeneity, which are characteristic of BPH. X-ray findings about prostate volume showed that 85% of the patients studied had an increase in prostate volume, enlarged soft tissue shadow in the caudal abdomen or cranially to the pelvis but caudally to the bladder. These data were found out in 13% more patients than those with ultrasound data for BHP. In this study, computed tomography demonstrated structural changes and precise prostate size in all 10 patients with suspected BPH. The CASA results showed that the percentage of static sperm was significantly higher in dogs with BPH than in healthy dogs. At the same time, there was a decline in the percentage of cells with progressive movement at a rapid and medium rate of movement in patients with BPH compared to those data in healthy dogs. These changes could have a negative effect on the fertilising potential of the sperm. The obtained results suggested that the application of CT and CASA for early diagnosis of BPH in dog breeders from rare and valuable breeds is advisable and useful for timely prevention and treatment of the disease.

Imaging of the male reproductive tract: Not so easy as it looks like

Diagnostic imaging is one of the most important tools in the breeding soundness evaluation of dogs and cats with reproduction problems. In recent years several imaging techniques have been developed, trying to aid the diagnosis and to differentiate between abnormal findings. This review presents the current knowledge on the imaging of normal and abnormal testes, spermatic cord, excurrent duct system, scrotum, accessory sex glands, penis and muscles for protrusion, erection and ejaculation of the dog and of cat. It also highlights the weak points and disadvantages of each imaging technique.

Assessment of the age for a preventive ultrasonographic examination of the prostate in the dog

The prostate commonly develops benign prostatic hyperplasia (BPH) in dogs over 5 years, while in aged dogs other pathological findings might be revealed by ultrasonographic exam. The aim of the present study was to estimate the most suitable age for a preventive ultrasonographic examination of the prostate in the dog. The prostate of 1003 intact male dogs of 64 different breeds, of different ages (1-18 years) and bodyweights (2-55 kg) was evaluated with ultrasound, irrespective of the reason for clinical examination. The age of each dog was expressed as the ratio between the actual age and the maximum longevity expected for the breed. Dogs were divided in two groups based on breeds' life expectancy as short life (SL) and long life (LL). The size of the prostate (normal, enlarged or small) and the presence of abnormal sonographic findings were recorded for each dog. The results of the present study indicate that the most suitable age for a preventive ultrasonographic exam of the prostate in the dog is approximately at 40% of its expected longevity, both in short and long life breeds, because at this age there is a strong possibility to be able to detect abnormal prostatic findings. In 47.5% of the dogs at least one abnormal finding of the prostate was revealed by ultrasonographic exam, while dogs with long life expectancy showed a significantly higher prevalence of abnormalities, than dogs with short life expectancy. The most frequent findings were the increase of prostatic size (33.5%) and the presence of at least one cyst (33.6%), with no difference between SL and LL dogs. In conclusion, a preventive examination of the prostate starting at 40% of expected longevity in dogs of short and long life breeds is strongly recommended for early detection of abnormalities, for scheduling specific follow up and for suggesting effective therapeutic protocols.

Computed tomography: a beneficial diagnostic tool for the evaluation of the canine prostate?

BACKGROUND

Prostatic diseases in intact male dogs are common. However, studies about the computed tomographic (CT) examination of the prostate in dogs are rare. The aim of the present study was to evaluate age related-changes in the canine prostate with the help of the CT and to evaluate whether measuring Hounsfield Units (HUs) in different morphological conditions of the prostate is of diagnostic value. Fifty pre- and post-contrast CT scans of the prostate of dogs were evaluated and divided into three groups according to the tissue structure: Group1 dogs with homogenous prostate tissue (16/50); group 2 with prostate cysts (26/50) and group 3 with inhomogeneous prostate tissue (8/50). The prostatic dimensions were measured and the ratio between length, height and width and the sixth lumbar vertebra was calculated. Median values of prostatic attenuation measured in HUs, using regions of interests (ROIs) were determined on pre- and post- contrast scans over the whole length of the prostate. The results were compared to the dog's age. Furthermore, the CT Images were compared with the results of ultrasonography (47/50).

RESULTS

On pre-contrast scans HUs within ROIs placed in the prostate did not differ statistically significantly between the different morphological groups (1: 37.7; 2: 36.3; 3: 39.8 HU). HUs within on the post- contrast scans showed statistically significant differences between the groups. Group one had a mean density of 93.6 HU, group two had a mean density of 106.1 HU and group three had one of 138.2 HU. The prostatic size in the first group was smaller than in the other groups, whereas the largest prostates were found in the second group. In six cases the post-contrast CT scan showed results that differed from the ultrasound examination. Dogs had a homogenous tissue in ultrasonography while the CT scan revealed an inhomogeneous tissue structure.

CONCLUSIONS

The CT examination can be a beneficial diagnostic tool for examining the prostatic size and for evaluating the prostatic tissue. The different HUs reflected age-related changes and alterations in the prostate while measuring the density of the prostate. Contrast agent application enables a more specific analysis of the prostate to be carried out and for precise changes in tissue structure to be observed.

Seminal Vesiculitis in Three Pet Rabbits ( Oryctolagus cuniculus )

To date, descriptions of pathologic conditions of the seminal vesicle in rabbits are scarce and limited to the laboratory animals in experimental conditions. The present article describes three cases of strangury, abdominal pain, and anorexia associated with seminal vesiculitis in pet rabbits. Three non-neutered male pet rabbits aged 3.6, 1.5, and 2.1 yrs were presented with strangury, abdominal pain, and anorexia. Seminal vesiculitis was diagnosed based on clinical signs and ultrasonography findings. Vesiculectomy was performed in two cases that presented strangury refractory to medical treatment, and diagnosis was confirmed by histopathology. In the third case, the patient received medical treatment, and a sequela in the form of lithiasis of the seminal vesicle was detected 3 yrs later. Plain radiographs were nearly unremarkable, and results from complete blood analysis and urinalysis were not specific in all three cases. Contrast radiography was performed in one case, showing a dilated seminal vesicle. Ultrasound and surgical biopsy seem to be the most sensitive techniques in the diagnosis of this pathology. Seminal vesiculitis must be included in the differential diagnosis of acute or chronic strangury in male pet rabbits.

Emergency laparoscopic cryptorchidectomy for acute abdomen due to testicular torsion in a dog

A 7-year-old male Siberian husky was presented with signs of acute abdomen. Based on the history and diagnostic imaging findings, torsion of an undescended abdominal testis was presumed. Emergency exploratory laparoscopy was performed and confirmed spermatic cord torsion in a non-neoplastic testis. The testis was enlarged and local peritonitis was evident. Laparoscopic cryptorchidectomy was performed and the dog recovered uneventfully. Histopathology confirmed thrombosis and necrosis. Laparoscopy is not only the method of choice for elective cryptorchidectomy, but can also be used in patients with acute abdomen from testicular torsion of an undescended testis.

Diagnosis of common prostatic conditions in dogs: an update

Prostatic diseases account for 3-10% of intact male dogs presented to veterinary surgeons. Conditions vary according to severity and frequency ranging from the most common, such as prostatic hyperplasia and cysts to the rarer conditions such as prostatic abcesses and neoplasia. Different causes of prostatic disease can often not be distinguished by evaluation of clinical signs, as these are not very distinctive and may be similar for many prostatic conditions. Understanding which additional diagnostic tools to use for each of the possible conditions is essential in making a correct diagnosis leading to the proper treatment. This article will discuss the different etiologies, age groups of dogs and the decision-making process which will help the practitioner to choose the right investigative tools, treatments and prognosis when dealing with prostatic disease.

Urinary tract disease in dogs: US findings. A mini-pictorial essay

Ultrasound (US) is the most commonly used imaging method for studying urinary tract disorders in dogs, as it is easy to perform, inexpensive and provides excellent contrast resolution in real-time. However, US examination of dogs presents a series of technical difficulties, and the US operator must therefore have a longstanding experience and access to high-quality equipment including a range of different probes to achieve a correct diagnosis. The aim of this mini-pictorial essay is to describe US findings and patterns which permit identification of the most common pathologies of the urinary tract in dogs. The technical difficulties that may be encountered are also evaluated as well as integration with other imaging modalities (traditional X-ray, computed tomography, magnetic resonance imaging).